The conversion of solid carbon sources to a gas has been developed many years ago. One process known as coal gasification contacts coal and steam under elevated temperature conditions to produce a gas consisting essentially of carbon monoxide and hydrogen, also called synthesis gas. The coal gasification processes are of great interest since they generally have the advantage of providing the potential of an environmentally clean process for coal utilization, of producing a high heating value gas which can substitute for natural gas or of producing a low heating value gas suitable for use as synthesis gas or subsequent conversion to hydrocarbons or chemicals or as boiler fuel.
The introduction of air in a coal gasification process is generally undesirable since large volumes of nitrogen have to be handled in the process. It would, therefore, be desirable to have a process available which uses a different oxygen source than air for the conversion of the carbon source into carbon monoxide. In addition, since the carbon monoxide forming reaction is generally an endothermic reaction, it would be desirable to have means available by which the heat necessary for this carbon monoxide forming reaction can be at least partially furnished from another process step such as to reduce the heat consumption in the process to a minimum.